The G+ collections are perhaps the best invention in G+. Gave me 20k+ followers. And I'm going to lose them all now... would love if it was possible to follow a set of "username+tag"'s instead of entire users. I don't care for 90% of what people post.
Reposts/resteems should always be placed in collections so that readers can filter them in or out depending on topic. G+ was great at this.
And communities... Love them.
Totally man, G+ had a lot of considerate UX features that really added to the experience and made it easier to curate and explore content. I do think Steemit has a huge UX problem and would to well to take a few pages out of G='s bok on how to structure a content based ad free platform